1. Field of the Invention
This invention relates to a one-piece golf ball comprising a ball body made from a white rubber composition, and a clear coat formed on the ball body without the application of a white paint.
2. Description of the Related Art
To yield brightly white surfaces of balls, conventional one-piece golf balls are covered with a white paint and are then covered with a clear coat. However, on a demand to provide a simplified coating process, attempts have been made to provide a one-piece golf ball comprising a ball body made from a white rubber composition and a clear coat formed on the surface of the ball body without coating of a white paint.
If the coat of a white paint is omitted, the ball body must be brightly white to ensure the appearance of the ball as white as conventional equivalents. However, such ball body made from a rubber composition cannot be significantly brightly white. In addition, the ball body made from a rubber is covered directly with a clear coat, the constitutive rubber is greatly deteriorated due to ultraviolet irradiation or ozone-induced oxidation. The deterioration of rubber due to ultraviolet irradiation or ozone-induced oxidation invites discoloring of the rubber ball body, and delamination of the clear coat due to deteriorated adhesion between the rubber ball body and clear coat.
Accordingly, it is an object of the invention to provide a one-piece golf ball comprising a ball body made from a white rubber composition, and a clear coat, the golf ball having a brightly white appearance and a satisfactory adhesion of the clear coat.
Specifically, the invention provides a one-piece golf ball comprising a ball body and a clear coat, wherein the ball body is made from a rubber composition including a matrix rubber, an xcex1, xcex2-unsaturated carboxylic acid and/or its metal salt, and an organic peroxide, and the clear coat being applied onto the surface of the ball body. In the golf ball, the rubber composition is a white rubber composition containing 0.5 to 5 parts by weight of a titanium oxide, and 0.001 to 0.1 part by weight of a blue pigment relative to 100 parts by weight of the matrix rubber, and the clear coat contains 0.02 to 0.5 part by weight of a fluorescent whitening agent, 0.05 to 3 parts by weight of an ultraviolet absorbent, and 100 parts by weight of a resinous component.